package com.wc.alorithm_luogu.P2415;

import java.util.Scanner;

/**
 * @Author congge
 * @Date 2023/4/24 15:16
 * @description https://www.luogu.com.cn/problem/P2415
 * 集合求和
 */
public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long sum = 0;
        int n = 0;
        while (sc.hasNextLong()) {
            sum += sc.nextLong();
            n++;
        }

        System.out.println(sum * (long) (Math.pow(2, n - 1)));
    }
}
